Orthopedic device

ABSTRACT

An orthopedic device for fixating bone parts includes a set of one or more bone fixation pins for engaging a bone piece, an elongated fixator body having an internally threaded bore extending longitudinally therethrough, a pair of opposed longitudinally extending slots in the fixator body, and a pin-holder received within the fixator body and configured to removably hold the set of one or more bone fixation pins. The pin-holder is longitudinally movable within the fixator body for controlling the position of the set of bone fixation pins within the fixator body. The fixator body also can be configured to removably hold a second set of one or more bone fixation pins at a location fixed along the fixator body.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Divisional application of U.S. Ser. No.12/262,628, filed Oct. 31, 2008, now U.S. Pat. No. 8,057,473 and claimsthe benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser.No. 60/984,012, filed Oct. 31, 2007, and U.S. Provisional ApplicationSer. No. 61/096,358, filed Sep. 12, 2008. The disclosures of theforegoing applications are incorporated herein by reference in theirentirety.

FIELD OF THE INVENTION

The present disclosure relates to the field of orthopedics and moreparticularly to an external orthopedic device for providing fixation,reduction, or distraction of bone segments.

BACKGROUND

External orthopedic devices are used in many orthopedic treatments tofixate, distract, or reduce bone segments. Generally, fixation devicesor fixators are used to stabilize bone pieces and to facilitate thehealing of bones at a bone repair site. Such fixators can be used byorthopedic surgeons to restore the patient's anatomy at a fracturefollowing an injury or distract an osteotomy site in bone lengtheningprocedures. Reduction and distraction devices are used to graduallyadjust the relative orientation and spacing of the bone parts onopposing sides of a bone repair site. Because these external devices areattached externally to the patient's body for the duration of thetreatment, which can last from several weeks to many months, thebulkiness of the external fixator devices are important features in themarket acceptance of any particular design.

Thus, there is a continuing need for an improved external fixator thatis adaptable to a variety of configurations while maintaining a lowprofile for physical compactness.

SUMMARY

According to an embodiment, an external fixator device for fixating boneparts is disclosed. Such device can be used in treating bone fracturesor osteotomies. In treating bone fractures, the device can be used tohold the bone pieces in place. The device can be used for compression ordistraction of the bone parts.

According to an embodiment, an orthopedic device for fixating bone partsincludes a set of one or more bone fixation pins suitable for engaging abone piece, an elongated fixator body having an internally threaded boreextending longitudinally therethrough, a pair of opposed longitudinallyextending slots in the fixator body, and a pin-holder received withinthe fixator body and configured to removably hold the set of one or morebone fixation pins, the pin-holder longitudinally movable within thefixator body for controlling the position of the set of bone fixationpins within the fixator body. The orthopedic device can have the fixatorbody configured to removably hold a second set of one or more bonefixation pins at a location fixed along the fixator body.

According to another embodiment, an orthopedic device for fixating boneparts comprises a set of one or more bone fixation pins suitable forengaging a bone piece, a fixator body having an internally threaded boreextending longitudinally therethrough, a first pair of opposedlongitudinally extending slots in the fixator body, and a pin-holderreceived within the internally threaded bore of the fixator body andconfigured to removably hold the set of one or more bone fixation pinsextending through the pair of opposed longitudinally extending slots.The pin-holder is longitudinally movable within the fixator body forcontrolling the position of the set of bone fixation pins within thefixator body.

According to another embodiment, an orthopedic device for fixating boneparts comprises two sets of one or more bone fixation pins suitable forengaging a bone piece, a fixator body having a first part and a secondpart, and the first and second parts being connected by a joint. Thejoint can comprise a universal joint or double-jointed with twouniversal joints. Each of the first and second parts has an internallythreaded bore extending longitudinally therethrough and a first pair ofopposed longitudinally extending slots in the first part of the fixatorbody. A first pin-holder is received within the internally threaded boreof the first part and configured to removably hold the first set of oneor more bone fixation pins extending through the first pair of opposedlongitudinally extending slots. The pin-holder is longitudinally movablewithin the first part for controlling the position of the set of bonefixation pins within the first part. A second pair of opposedlongitudinally extending slots are provided in the second part of thefixator body. A second pin-holder is received within the internallythreaded bore of the second part and configured to removably hold thesecond set of one or more bone fixation pins extending through thesecond pair of opposed longitudinally extending slots, the pin-holderlongitudinally movable within the second part.

According to another embodiment, a method of fixating two bones relativeto one another is disclosed. The method comprises percutaneously placinga first fixation pin into a first bone piece, placing an externalfixator over the first fixation pin by having the fixation pin gothrough a pin hole provided at one end of the external fixator'selongated body, wherein the elongated body has two ends and aninternally threaded bore extending longitudinally therethrough. Theelongated body's second end is then positioned over a second bone piece.A pin-holder configured to move longitudinally within the internallythreaded bore and removably hold one or more fixation pins, ispositioned along the length of the elongated body at a desired locationover the second bone piece. Next, a second fixation pin is insertedthrough a pin hole provided in the pin-holder and into the second bonepiece. Then, the second fixation pin is locked by tightening a set screwprovided in the pin-holder are toxic. The first fixation pin is lockedby tightening a locking set screw provided within and threadablyengaging the internally threaded bore of the elongated body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an illustration showing a perspective view of an externalfixator according to another embodiment.

FIG. 1B is a plan view of the external fixator of FIG. 1A.

FIG. 1C is a cross-sectional view of the fixator of FIG. 1B takenthrough line B-B.

FIG. 1D is an opposite side plan view of the view shown in FIG. 1B.

FIG. 1E is a cross-sectional view of the fixator of FIG. 1D takenthrough line A-A.

FIG. 2A is a plan view of an embodiment of a pin holder assembly.

FIG. 2B is a cross-sectional view of the pin holder assembly of FIG. 2Ataken through line A-A shown in FIG. 2A.

FIG. 3A is a plan view of an external fixator according to anotherembodiment.

FIG. 3B is a sectional view of the universal joint of the externalfixator of FIG. 3A taken through line A-A shown in FIG. 3A.

FIG. 3C is a plan view of an external fixator according to anotherembodiment.

FIGS. 3D and 3E are longitudinal sectional views taken through line B-Bshown in FIG. 3D illustration two embodiments of a portion of theexternal fixator of FIG. 3C.

FIGS. 4A-4C illustrate a hand tool set for use with the external fixatorof this disclosure.

FIGS. 5A-5H illustrate a method of using an embodiment of the fixator ofthis disclosure to fixate two bones in a foot.

FIGS. 6A and 6B illustrate an application of the fixator of thisdisclosure in a spine.

FIGS. 7A-7C illustrate an application of the fixator of this disclosurein various long bone applications.

FIGS. 8A and 8B are perspective views of a fixator according to anotherembodiment.

FIGS. 9A-9H are various additional views of the fixator of FIGS. 8A and8B.

FIGS. 10A and 10B are perspective views of a fixator according toanother embodiment.

FIGS. 10C-10F are various additional views of the fixator of FIGS. 8Aand 8B.

FIGS. 11A and 11B are perspective views of a fixator according toanother embodiment.

FIGS. 11C-11F are various additional views of the fixator of FIGS. 8Aand 8B.

FIGS. 12A-12F are various views of another universally flexible jointaccording to another embodiment.

FIG. 13A is an illustration of an external fixator according to anembodiment.

FIG. 13B is an illustration of an external fixator according to anotherembodiment.

FIG. 13C is an illustration of another embodiment of external fixator.

FIG. 14A is an illustration of the fixator body of the external fixatorof FIG. 13A.

FIG. 14B is an illustration of the slidable sleeve for the fixator ofFIG. 13A.

FIG. 14C is a lateral cross-sectional view of the fixator of FIG. 13A.

FIG. 14D is a longitudinal cross-sectional view of the fixator of FIG.13A.

FIG. 14E is another longitudinal cross-sectional view of the fixator ofFIG. 13A.

FIG. 15A is a perspective view of a pin locking cap.

FIG. 15B is a partial sectional illustration of the pin locking cap ofFIG. 15A in an assembled configuration in an unlocked position.

FIGS. 15C and 15D are illustrations showing how the spring-loaded pinlocking cap 30 locks bone fixation pins.

FIG. 16 is an illustration of an external fixator according to anotherembodiment.

FIG. 17A is a detailed illustration of another embodiment of a drivingset screw and the associated fixation pin holder.

FIG. 17B is a cross-sectional view of the driving set screw of FIG. 17A.

FIG. 17C is a longitudinal cross-sectional view of the fully assembleddriving set screw of FIG. 17A.

FIG. 17D is an illustration of a cam component of the external fixatorof FIG. 16.

FIG. 17E is an end view of the cam of FIG. 17D.

FIG. 18A is an illustration of another embodiment of a slidable sleevethat can be used in conjunction with the driving set screw of FIG. 17A.

FIG. 18B is an illustration of an external fixator utilizing theslidable sleeve of FIG. 17A.

FIG. 19A is an illustration of a slidable sleeve according to anotherembodiment.

FIG. 19B is a longitudinal cross-sectional illustration of the slidablesleeve of FIG. 19A.

FIG. 19C is an illustration of a countersink-head screw used inconjunction with the slidable sleeve of FIG. 19A.

FIG. 19D is a cross-sectional illustration of a fixator body utilizingthe slidable sleeve of FIG. 19A.

FIG. 20A is an illustration of an offset pin clamp.

FIG. 20B is an end view of the offset pin clamp of FIG. 20A.

FIG. 20C is a longitudinal cross-section of the offset pin clamp ofFIGS. 20A and 20B taken through the line A-A.

FIG. 21 is an illustration of an external fixator according to anotherembodiment.

FIG. 22 is an illustration of an external fixator according to anotherembodiment.

FIG. 23A is an illustration of the slidable sleeve of FIG. 19A incombination with a rotatable pin clamp attachment.

FIG. 23B is an illustration of the offset pin clamp of FIG. 20A incombination with a rotatable pin clamp attachment.

FIG. 23C is a longitudinal cross-sectional illustration of the assemblyof FIG. 23B.

FIG. 23D is a detailed illustration of the rotatable pin clampattachment.

The features shown in the above referenced drawings are illustratedschematically and are not intended to be drawn to scale nor are theyintended to be shown in precise positional relationship. Like referencenumbers indicate like elements.

DETAILED DESCRIPTION

In the following detailed description of the preferred embodiments,reference is made to the accompanying drawings which form a part hereof,and in which are shown by way of illustration specific embodiments inwhich the invention may be practiced. It is to be understood that otherembodiments may be utilized and structural changes may be made withoutdeparting from the scope of the present invention.

Referring to FIGS. 1A-1E, an external fixator device 5 according to apreferred embodiment will be described. The external fixator device 5includes a fixator body 110 having an internally threaded bore 111extending longitudinally through the length of the fixator body 110. Apin-holder 143 is received in one end of the fixator body 110 andthreadably engages the internally threaded bore 111 enabling thepin-holder 143 to move longitudinally inside the fixator body. Thepin-holder 143 is provided with one or more pin holes 142 extendinglaterally through the pin-holder 143 for receiving a set of one or morebone fixation pins 5 a. The lateral orientation of the pin holes 142refer to the fact that the pin holes 142 extend through the pin-holder143 generally sideways with respect to the longitudinal axis of thefixator body. The pin holes 142 can be oriented perpendicular to thelongitudinal axis of the fixator body or at any desired angle. Thefixator body can have cylindrical shape as shown in the illustratedexample but the fixator body can have any appropriate shape.

As shown in FIG. 1A, two pairs of diametrically opposed longitudinallyextending slots 116 and 126 are provided in the fixator body 110. Thefirst pair of longitudinally extending slots 116 and the pin holes 142provided in the pin-holder 143 allows one or more first set of fixationpins 5 a (shown in phantom lines) to be removably received in the pinholes 142 and pass through the fixator body 110. The illustrated exampleis shown with two fixation pins 5 a but the pin-holder 143 can beconfigured to accommodate as many fixation pins 5 a as appropriate. Theslots 116 allow the pin-holder 143 to be moved longitudinally within thefixator body 110 while holding the first set of fixation pins 5 a. Aguide pin 160 is provided in the pin-holder 143 to keep the pin-holderfrom rotating and keep the pin holes 142 aligned with the slots 116. Theexample of a guide pin 160 shown in FIG. 1A is a cylindrical pin but thepin is not limited to that shape and can be provided in any shape aslong as it functions substantially the same way. The guide pin 160, forexample, can have a square or hexagonal cross-sectional shape.

Referring to the cross-sectional views shown in FIGS. 1C and 1E, thepin-holder 143 threadably engages the internally threaded bore 111 bymeans of a threaded driving screw 155. The driving screw 155 rotatablyengages the pin-holder 143 and as the head portion is threaded in or outof the fixator body 110, it pushes or pulls the pin-holder 143longitudinally within the bore 111.

The pin-holder assembly is inserted into the internally threaded bore111 with the pin-holder 143 end first so that the threaded driving screw155 is near the first end 117 of the fixator body 110 as shown in FIG.1C. The driving screw 155 threadably engages the internally threadedbore 111 and operates on the pin-holder 143 to move the pin-holder 143back and forth within the bore 111 in longitudinal direction. To enablethis, the driving screw 155 and the pin-holder 143 are rotatably andaxially coupled so that the threaded driving screw 155 can be rotatedaxially with respect to the pin-holder 143 while the pin-holder 143 isholding the fixation pins 5 a. The driving screw 155 is provided with asocket 157 at the end opposite from the end rotatably coupled to the pinholder 143. The socket 157 is appropriately shaped to receive a tool forturning the driving screw 155.

The rotatable axial coupling between the driving screw 155 and thepin-holder 143 can be achieved in a variety of ways. In one embodiment,this rotatable axial coupling is achieved by the exemplary structuresshown in FIG. 1C. In this example, the pin-holder 143 has a center stem145 that extends into the threaded driving screw 155. The center stem145 has a flared head portion 146 having a larger diameter than thecenter stem 145. The center stem 145 including the head portion 146 isreceived in a recess of the driving screw 155 defined by alongitudinally extending flange 159. The flared head portion 146interferes with a portion of the flange 159 so that the pin-holder 143and the driving screw 155 are secured together in longitudinal directionwhile allowing the pieces to rotate with respect to each other.

The flange 159 extends partially along the periphery of the drivingscrew 155 leaving an opening so that the driving screw 155 and thepin-holder 143 can be assembled by sliding the center stem 145 throughthe opening into the recess. As mentioned earlier, however, therotatable coupling structure between the pin-holder 143 and the drivingscrew 155 is not limited to the configuration discussed. For example,the coupling structure shown in FIG. 1C can be reversed so that thecenter stem 145 is provided on the driving screw 155 and thelongitudinally extending flange 159 is provided on the pin-holder 143.Furthermore, the head portion 146 of the center stem 145 can have aspherical shape rather than the flat shape illustrated in FIGS. 1C and1E.

As shown in FIG. 1C, set screws 186 are provided in the pin-holder 143for locking the first set of fixation pins 5 a in their correspondingpin holes 142. The pin-holder 143 is provided with at least one threadedbore 184 for each pin hole 142 for receiving a set screw 186. Each ofthe set screws 186 threads into the threaded bore 184 corresponding to apin hole 142 and secures a bone fixation pin that is received in the pinhole 142 by impinging against the bone fixation pin.

In the illustrated example, the threaded bores 184 are aligned with thesecond set of slots 126 so that the set screws 186 are accessiblethrough the slots 126 for tightening or loosening. According to anaspect of the invention, the threaded bores 184 can extend completelythrough the opposite side of the pin-holder 143 so that set screws 186can be threaded in to the pin-holder 143 from either side through eitherone of the second set of slots 126. According to another aspect of theinvention, some of the pin holes 142 in the pin-holder 143 can beoriented to align with the first set of slots 116 and other pin holes142 can be oriented to align with the second set of slots 126. Thepin-holder 143 can be provided with one or more pin holes 142, thespecific number depending on the maximum number of fixation pins 5 a theparticular fixator device requires.

FIGS. 2A and 2B shows a pin-holder 243 according to another embodiment.The pin-holder 243 is also configured to rotatably couple to a drivingscrew 155. Similar to the pin-holder 143, the pin-holder 243 is alsoconfigured with a center stem 145 that is received into the recess inthe driving screw 155 formed by the longitudinally extending flange 159.The center stem 145 of the pin-holder 243 has a flared head portion 146that interferes with a portion of the flange 159 when they are coupledso that the pin-holder 243 and the driving screw 155 are securedtogether in longitudinal direction while they can rotate with respect toeach other. As discussed above, this coupling structure is only oneexample and other suitable coupling structure can be used.

As shown in FIGS. 2A and 2B, the flange 159 extends partially along theperiphery of the driving screw 155 leaving an opening 158 so that thedriving screw 155 and the pin-holder 243 can be assembled by sliding thecenter stem 145 through the opening 158 into the recess.

The pin-holder 243 illustrates an embodiment wherein the relativepositions of the pin holes 142 and the guide pin 160 are different fromthose of the pin-holder 143. In the pin-holder 243, one or more pinholes 142 are positioned on one side of the guide pin 160 so that thepin holes 142 can be positioned closer together. The positions of thethreaded bores 184 for the set screws 286 are aligned with the pin holesso that the set screws 286 can lock the first set of fixation pins 5 areceived in the pin holes 142. In this embodiment, the threaded bores184 extend completely through the pin-holder 243 and actually only oneend 184 a of a bore 184 is threaded to threadably engage the set screws286. The set screws 286 are inserted into their respective bore 184 fromthe non-threaded end. The set screws 286 are provided with a socket 287at one end appropriately shaped for receiving a tool for turning the setscrews. Thus, the socket end 287 extends out as shown in FIG. 2B. Theopposite end, the end that will be urged against a fixation pin receivedin the pin hole 142, of the set screws 286 have a flared portion 286 awhose diameter is larger than the diameter of the threaded portion 184 aof the bore 184 functioning as a stop and prevents the set screws 286from being completely removed through the threaded end 184 a. Thisfeature allows the end user to loosen or unscrewing the set screws 286without worrying about the set screws 286 falling out of the pin-holder243 while unscrewing.

The fixator body 110 may be provided with at least one pair of opposedpin holes 112 a and 12 b near the fixator body's second end 118 forreceiving one or more second set of fixation pins 5 b (shown in phantomlines in FIG. 1A) through the fixator body. Similar to the pin holes 12provided in the embodiment of FIG. 13A, for example, a pair of opposedpin holes 112 are provided for each of the fixation pins 5 b. The pinholes for receiving the second set of fixation pins 5 b can bediametrically (with respect to the diameter of the fixator body 110)opposed like the pin holes 112 a and 112 b or they can be off-set fromthe diameter of the fixator body 110 like the pair of pin holes 112 cand 112 d shown in FIGS. 1A and 1B. Regardless, the fixator body 110 canbe provided with as many sets of such pin holes as many second set offixation pins 5 b are necessary. Furthermore, the pin holes 112 a, 112b, 112 c and 112 d can be positioned so that the second set of fixationpins 5 b can be at any desired angle with respect to the longitudinalaxis of the fixator body 110.

At the second end 118 of the fixator body 110, a locking set screw 125is received in and threadably engages the internally threaded bore 111of the fixator body for locking the second fixation pins 5 b. The mannerin which the second fixation pins 5 b cooperates with the rest of theexternal fixator device 5 is similar to that described in connectionwith the embodiment of the external fixator device 1 described above.The locking set screw 125 is provided with a socket 127 appropriatelyshaped to receive a tool for turning the set screw 125.

FIG. 3A shows another embodiment of the external fixator 5 of FIGS.1A-1E. In this embodiment, the fixator body 110 is configured with auniversal joint 500 between two portions 110A and 110B of the fixatorbody 110. The universal joint allows the two portions 110A and 110B ofthe fixator body to be set at any desired angle, which in turn allowsthe fixation pins held in each of the two portions 110A and 110B of theexternal fixator. The universal joint is formed by hinge legs 502 and504 of the two portions 110A and 110B, respectively, joined by adouble-axle 505, which is a typical universal joint construction. Thedouble-axle 505 can be configured to allow locking of the universaljoint at a desired angle. FIG. 3B, a cross-section of the universaljoint taken through the line A-A shown in FIG. 3A, shows that thedouble-axle 505 can include a locking screw 507 a and 507 b for each ofthe two axes of the universal joint. The locking screws 507 a and 507 bthreads into the main body of the double-axle 505 and locks theuniversal joint 505 in each of the two axes by compressing therespective hinge legs 504 and 502.

FIG. 3C shows another embodiment wherein the second portion 110B of thefixator body is configured to freely rotate axially with respect to theuniversal joint body 520. FIG. 3D, which is a longitudinal sectionalview of the second portion 110B of the fixator body taken through theline B-B of FIG. 3C, shows an example of that structure that allows thefree axial rotation of the second portion 110B. One end of the universaljoint body 520 is received within the threaded bore 111B of the secondportion 110B. The universal joint body 520 and the second portion 110Bhave flanges 522 and 122, respectively, which interfere with one anotherto keep the universal joint body 520 from being pulled out of the secondportion 110B when the fixator 5 is used in distraction mode. On theother hand, a retaining pin 166 inserted across the second portion 110Bprevents the universal joint body 520 from being pushed into the secondportion 110B when the fixator 5 is used in compression mode. FIG. 3Eshows an embodiment where a set screw 132 for locking the free-spinninguniversal joint body 520 is provided in the second portion 110B of thefixator body. The set screw 132 threadably engages the second portion110B and advances inward urging against the flange portion 522 of theuniversal joint body 520 to lock the universal joint body 520.

FIG. 4A shows a hand tool set 600 that can be provided along with theexternal fixator device of this disclosure. The hand tool set 600includes a screwdriver 610 and an adaptor 650. The screwdriver 610 isfor the user of the external fixator device such as a surgeon to tightenor loosen the various set screws that are used in the external fixatordevice. The driver includes a handle portion 612 and a driving tip 615(i.e. the part that engages the set screws). The driving tip 615 isconfigured and adapted appropriately for engaging the set screw. Forexample, the driving tip 615 is shown in FIG. 4B with a square tip 616for driving a Robertson-type screw heads. This example of a screwdriver610 is double-tipped and includes a second driving tip 617 which is asmaller square tip. Thus, the user can use this one screwdriver 610 fordriving two different size screw heads.

In the external fixator embodiment of FIGS. 1A-1C, for example, thescrewdriver 610 can be appropriately configured and adapted to engagethe sockets of the set screws 125, 155, and 186. As discussed above, theset screws can have any one of the variety of driver socket shapes andthe screwdriver 610 would be configured with an appropriately matchingdriving tip 615.

As an example, FIG. 4B shows another embodiment of the screw driver 610′having a driving tip 615 configured as a double-hex tip. The driving tip615 is configured with two different size hex driving tips 616′ and617′.

The adaptor 650 is configured to be used for driving bone fixation pinsinto a bone piece and for removing the bone fixation pins. The adaptor650 is provided with a screwdriver connector end 652 at one end and abone fixation pin engaging end 655 at the other end. The fixation pinengaging end 655 is provided with a socket appropriately shaped toreceive the distal end of a bone fixation pin. If the distal end of thebone fixation pin has a square shaped tip, as many fixation pins do, thefixation pin engaging end 655 will be provided with a square shapedsocket.

The screwdriver connector end 652 is configured and adaptedappropriately for engaging a particular screw driver or a power driverthat may be used to drive or remove the bone fixation pins. In theexample shown in FIG. 4A, the screwdriver connector end 652 is providedwith a square-shaped socket 657 for receiving the square-shapedscrewdriver tip 617. FIG. 4C shows a bone fixation pin 700 engaged withthe adaptor 650 and the adaptor 650 in turn being driven by thescrewdriver 610.

According to another embodiment, the screwdriver connector end 652 ofthe adaptor 650 is configured to be engaged to a power screwdriver'schuck. In the example shown in FIG. 4A, the screwdriver connector end652 is provided with a flat surface 658 that is required for engagingwith a particular type of power screwdriver chuck that is in use in theindustry.

The adaptor can also be provided with a hole 654 for receiving the screwdriver 610 as shown in FIG. 4A to provide more leverage when the bonefixation pins are manually being driven. This arrangement provides moretorque than the arrangement shown in FIG. 4C.

A method of using an embodiment of the external fixator device to fixatetwo bones in a foot will be described as an example of methods for usingthe external fixator of this disclosure. Referring to FIG. 5A, thethreaded end of a first fixation pin 701 is placed freehandperpendicular to the long axis of the bone 801. FIGS. 5A-5H areillustrated using a skeletal model of a foot but in actual use thefixation pins will be driven into the bone percutaneously. The fixationpin diameter should not exceed ⅓ of the bone diameter. Referring to FIG.5B, the external fixator 5 of FIGS. 1A-1E is placed over the firstfixation pin 701 (the fixation pin going through one of the pin hole 112a) and aligned so that the distally located pin-holder 143 of thefixator 5 is positioned over the second bone 802. The pin-holder 143should be adjusted along the length of the fixator 5 to position the pinholes 142 (see FIG. 1C for the pin holes 142 in the pin-holder 143) inthe desired location.

Referring to FIG. 5C, a second fixation pin 702 is inserted through oneof the pin holes 142 and into the second bone 802. During this step, thepin-holder 143 functions as a guide for threading the second fixationpin 702 into the second bone 802. At this point, fluoroscopy can be usedto check penetration of the pins 701 and 702 through the far cortex ofthe bone. Pins should not penetrate more than 2 mm beyond the far cortexof bone.

Referring to FIG. 5D, a third and fourth fixation pins 703 and 704 areinserted through the fixator 5 in the same manner as the first twofixation pins and threaded into the first and second bone pieces 801 and801, respectively. The screw driver adaptor 650 of FIG. 4A can be usedto connect to the pins to assist with the insertion. As discussed abovein connection with FIGS. 4A-4C, a screw driver 610 can be connected tothe screwdriver connector end 652 of the adaptor 650 to manually advancethe fixation pins into the bone. If more torque is required, the screwdriver 610 can be inserted through the hole 654 as shown in FIG. 5E toadvance the fixation pins.

The fixator 5 provides at least two sets of pin holes 112 a and 112 c atthe proximal end 118 so that the proximal pins 701, 703 can bepositioned in either a vertical or horizontal configuration. Adequateclearance should be left between the fixator 5 and the patient's skin toallow for post-operative swelling.

Referring to FIG. 5F, the distal pins 702, 704 are locked by tighteningthe set screws 186 of the pin-holder 143 located within and accessiblethrough the fixator's slot 126. Referring to FIG. 5G, the proximalfixation pins 701, 703 are locked by tightening the locking set screw125 located in the threaded bore of the fixator 5 in the proximal end118 of the fixator 5. Referring to FIG. 511, compression or distractioncan be obtained by turning the driving screw 155 of the pin-holder 143located within the threaded bore of the fixator 5 accessible from thedistal end 117 of the fixator. For compression, the driving screw 155 isturned in the direction that will move the pin-holder 143, and thus thedistal fixation pins 702, 704, towards the proximal pins 701, 703. Thedirection of the turn will depend on the thread direction of thethreaded bore of the fixator 5. For distraction, the driving screw 155is turned in the opposite direction moving the pin-holder 143, and thusthe distal fixation pins 702, 704, away from the proximal fixation pins701, 703. For bone lengthening with a callotasis technique, for example,the distraction can be divided into ¼ turn increments where the threadson the internal bore of the fixator 5 is configured so that one fullturn of the screwdriver will result in 1 mm of distraction. After thefixator 5 is applied, the protruding ends 777 of the fixation pinsshould be cut short and capped with pin covers (not shown) or ifpossible, the fixator pin-holder 143 can be temporarily loosened so thatthe fixator 5 can be moved slightly away from the body to cover the cutends of the fixation pins. Perform a final check of all fixatorcomponents to ensure that they are tightened before completing thesurgery.

The various embodiments of the external fixator device described hereincan be used in treating other bones. For example, FIGS. 6A and 6B showsa fixator device such as the embodiment 5 of FIGS. 1A-1E, being used ina spine application. FIGS. 6A and 6B show two such fixator devices 5percutaneously attached to two vertebrae 901 and 902. The fixators 5 canbe used to fuse or decompress the vertebra 901, 902. FIGS. 7A-7C showmore examples where the fixator devices 5 are used in fixating orlengthening of various long bones. FIG. 7A shows the fixators 5 attachedto an ulna 903 and a radius 904. FIG. 7B shows the fixators 5 attachedto a femur 905 and a tibia 906. FIG. 7C shows the fixator 5 attached toa humerus 907.

FIGS. 8A, 8B, and 9A-9D show an external fixator 1000 that is anotherembodiment of the external fixator 5 of FIG. 3A. The external fixator1000 includes a first portion 1010A and a second portion 1010B that arelinked by a universal joint 1500. Similar to the universal joint 500 inthe external fixator 5 of FIG. 3A, the universal joint 1500 allows thetwo portions 1010A and 1010B of the fixator body to be set at anydesired angle, which in turn allows the fixation pins held in each ofthe two portions 1010A and 1010B of the fixator body to be arranged intoa variety of angular configurations. Similar to the external fixator 5,a set of fixation pins can be held in the first portion 1010A of theexternal fixator 1000 through the pin holes 142 in the pin-holder 143and another set of fixation pins can be held in the second portion 1010Bof the external fixator 1000 through the pin holes 112 a, 112 b, 112 cand 112 d.

The universal joint 1500 is formed by hinge legs 1502 a and 1502 b ofthe first portion 1010A and 1504 a and 1504 b of the second portion1010B, joined by a double-axle 1505. The universal joint 1500 can belocked by the hinge locking screws 1507 a and 1507 b are provided tolock the universal joint 1500 and lock the angular relationship betweenthe first and second portions 1010A and 1010B.

In one embodiment, the locking function of the hinge locking screws 1507a and 1507 b can be enhanced by providing diamond teeth surface finish(e.g. knurled surface finish) either on the interior surface of thehinge legs 1502 a and 1502 b or the surfaces on the double-axle 1505that come in contact with one another. Such diamond teeth finish willincrease the friction between the contacting surfaces when the hingelocking screws 1507 a, 1507 b are tightened. The first and secondportions 1010A and 1010B of the fixator may be made from materials thatare softer than the double-axle 1505 to further enhance this mechanicalbite of the diamond teeth.

As shown in the cross-sectional views of FIGS. 9A and 9D, thedouble-axle 1505 of the universal joint 1500 is different from thedouble axle 505 of the external fixator 5 shown in FIGS. 3A and 3B. Asshown in FIG. 9A, the hinge locking screw 1507 a extends from the hingeleg 1504 a to the hinge leg 1504 b completely through the double-axle1505 and holds the double-axle 1505 between the pair of hinge legs 1504of the second portion 1010B. The hinge locking screw 1507 a forms one ofthe two axle of the universal joint 1500 and allows the first and secondportions 1010A and 1010B to be rotated about the hinge locking screw1507 a in the direction illustrated by the arrow K in FIG. 9B. Thedouble-axle 1505 can be configured to have any appropriate shape as longas it fits within the universal joint configuration between the two setsof hinge legs 1502 a, 1502 b and 1504 a, 1504 b and accommodate thehinge locking screws 1507 a, 1507 b.

Because the hinge locking screw 1507 a extends completely through thesecond portion 1010B, the hinge locking screw 1507 a may be cannulatedfor K-wire alignment. The hinge locking screw 1507 a shown in FIG. 9A isprovided with a cannula 1508 that extends through the entire length ofthe hinge locking screw 1507 a. This allows the user to shoot a K-wirethrough the cannula 1508 to where the user prefers to place the hingeformed by the universal joint 1500.

As shown in FIG. 9A, the hinge locking screw 1507 a is provided withthreaded tip (away from its head) and threadably engages one leg of thepair of hinge legs 1504 a and 1504 b. In this illustrate example, thehinge locking screw 1507 a threadably engages the hinge leg 1504 b.Tightening the hinge locking screw 1507 a against the hinge leg 1504 bwill close the pair of hinge legs 1504 a and 1504 b together against thedouble-axle 1505 and lock the universal joint 1500 about the axle formedby the hinge locking screw 1507 a. This prevents the two portions 1010Aand 1010B from rotating in the direction of the arrow K.

The second axle of the universal joint 1500 is formed by the hingelocking screw 1507 b. However, as shown in FIG. 9D, which is across-sectional view of the external fixator 1000 taken through theplane C-C in FIG. 9C that is perpendicular to the cross-sectional viewshown in FIG. 9A, because the hinge locking screw 1507 a extendscompletely through the double-axle 1505, the hinge locking screw 1507 bcan not extend completely through the double-axle 1505. Rather, thehinge locking screw 1507 b threadably engages the double-axle 1505 whileallowing the hinge leg 1502 b of the first portion 1010A to rotate aboutthe hinge locking screw 1507 b in the direction illustrated by the arrowH in FIG. 9C. Tightening the hinge locking screw 1507 b against thedouble-axle 1505 will lock the double-axle 1505 against the hinge leg1502 b and lock that hinge.

Because the hinge locking screw 1507 b does not extend through thedouble-axle 1505, the opposite side of the double-axle 1505 is rotatablyattached to the hinge leg 1502 a by a hinge pin 1507 c. The hinge pin1507 c may be securely attached to the hinge leg 1502 a and extend intothe double-axle 1505. For example, the hinge pin 1507 c may bepress-fitted into the hinge leg 1502 a or welded to the hinge leg 1502a. The hinge pin 1507 c in combination with the hinge locking screw 1507b comprise the second axle of the universal joint 1500.

The first portion 1010A of the external fixator 1000 is structurallyequivalent to the first portion 110A of the external fixator 5. Similarto the first portion 110A, the first portion 1010A has an internallythreaded bore 1111A extending longitudinally through the length of thefirst portion 1010A (see FIG. 9A). A pin-holder 143, shown and describedin detail with reference to FIGS. 1A-1D, 2A, 2B and 3A, is received in afirst end 1012 of the first portion 1010A of the external fixator 1000and threadably engages the internally threaded bore 1111A. Thisconfiguration enables the pin-holder 143 to move longitudinally insidethe first portion 1010A. The first and second portions 1010A and 1010Bcan have cylindrical shapes as shown in the illustrated example but theycan have any appropriate shape.

The first portion 1010A is provided with a pair of diametrically opposedlongitudinally extending slots 116 that cooperate with the guide pin 160of the pin-holder 143 to guide the longitudinal movement of thepin-holder 143 and to keep the pin holes 142 aligned with thelongitudinally extending slots 116. The first portion 1010A of theexternal fixator 1000 is also provided with at least one longitudinallyextending slot 126 for accommodating the set screws 186 of thepin-holder 143. In the illustrated example, the set screws 186 threadinto the pin-holder 143 in perpendicular orientation to the pin holes142. Thus, the longitudinally extending slot 126 is locatedappropriately on the first portion 1010A to accommodate the set screws186. The longitudinally extending slot 126 can be provided in the firstportion 1010A as a diametrically opposed pair to allow the set screws186 to be threaded into the pin-holder 143 from the opposite side of theexternal fixator 1000 if necessary.

FIG. 1C shows how a set of fixation pins 5 a may be held by thepin-holder 143. Further details on how the pin-holder 143 holds fixationpins 5 a and operate within the first portion 1010A is provided in thetexts accompanying the FIGS. 1A-1D, 2A, 2B and 3A.

The second portion 1010B of the external fixator 1000 holds a set offixation pins via the pin holes 112 a, 112 b, 112 c and 112 d, similarto the external fixator 5 of FIGS. 1A-1E and 3A. As shown in thecross-sectional views of FIGS. 9A and 9D, however, the second portion1010B is provided with a pin-locking mechanism inside its tubularstructure. The pin-locking mechanism comprises a threaded driving screw1125 and a pin-locking block 1130. The threaded driving screw 1125 andthe pin-locking block 1130 are configured to rotatably couple togethersimilar to the way the pin-holders 143 and 243 of FIGS. 1C and 2A arecoupled to the threaded driving screw 155. The threaded driving screw1125 threadably engage the internal threaded bore 1111B of the secondportion 1010B and the driving screw 1125 moves the pin-locking block1130 inwardly or outwardly within the second portion 1010B by turningthe driving screw. The driving screw 1125 is configured with a recess1127 for receiving a tool (e.g. a wrench, screw driver, etc.) forturning the driving screw 1125.

The pin-locking block 1130 is appropriately sized to fit within theinternal bore of the second portion 1010B and move longitudinally. Thepin-locking block 1130 is provided with pin holes 1132 and 1133 thatalign with the pin holes 112 a, 112 b, 112 c, and 112 d of the secondportion 1010B. As shown in the cross-section of FIG. 9D, when the pinholes 1132 and 1133 are aligned with the pin holes 112 a, 112 b, 112 c,and 112 d, fixation pins can be inserted through these holes. By drivingthe driving screw 1125 inwardly or outwardly, the pin-locking block 1130is pushed inwardly and urged against the fixation pins that areextending through the pin holes 1132 and 1133 of the pin-locking block1130. This results in the fixation pins being braced against the pinholes 112 a, 112 b, 112 c, and 112 d thus locking the fixation pinswithin the second portion 1010B.

Furthermore, according to another embodiment, the second portion 1010Bof the external fixator 1000 may be provided with a lock indicatorwindow 1020. As shown in FIG. 9A, the pin-locking block 1130 is providedwith a lock indicator pin 1022 that is affixed into the pin-lockingblock 1130. The lock indicator pin 1022 protrudes from the pin-lockingblock 1130 and extends into the lock indicator window 1020. The lockindicator pin 1022 moves in longitudinal direction along with thepin-locking block 1130 and the position of the lock indicator pin 1022within the lock indicator window 1020 indicates whether the pin-lockingblock 1130 is in a locked position or an unlocked position. For example,in the illustrated example, the lock indicator pin 1022 in the positionshown in FIG. 9B, positioned away from the universal joint 1500, thepin-locking block 1130 is in an unlocked position. When the drivingscrew 1125 is threaded inwardly pushing the pin-locking block 1130inward, the lock indicator pin 1022 would also slide inwardly within thelock indicator window 1020 and be closer to the universal joint 1500. Itis noted that the longitudinal motion of the pin-locking block 1130would be limited by the length of the lock indicator window 1020 in thelongitudinal direction.

FIGS. 9F and 9H are lateral cross-sectional views of the second portion1010B of the external fixator 1000 taken through the planes D-D and E-Eof FIG. 9G and shows further detailed views of the pin-locking block1130. As shown in the cross-sections, the pin-locking block 1130 is acylindrical structure that has two flats surfaces. The interior bore1111B in the region G shown in FIG. 9E is configured with correspondinginwardly protruding portions 1015. This configuration prevents thepin-locking block 1130 from rotating within the interior bore 1111B andmaintain the alignment between the pin holes 1132, 1133 of thepin-locking block 1130 and the pin holes 112 a, 112 b, 112 c, 112 d ofthe second portion 1010B.

FIGS. 10A, 10B, and 10C-10F show an external fixator 2000 according toanother embodiment. The external fixator 2000 includes a first portion1010A and a second portion 1010C that are linked by a universal joint1500, similar to the universal joint 1500 in the external fixator 1000of FIG. 8A. The universal joint 1500 allows the two portions 1010A and1010C of the fixator body to be set at any desired angle, which in turnallows the fixation pins held in each of the two portions 1010A and1010C of the fixator body to be arranged into a variety of angularconfigurations.

The first portion 1010A and the universal joint 1500 of the externalfixator 2000 have the same structures as the first portion 1010A and theuniversal joint 1500 of the external fixator 1000. As shown in FIGS. 10Dand 10E, the universal joint 1500 allows the first portion 1010A and thesecond portion 1010C to rotate about the two axles of the universaljoint 1500 in the directions indicated by the arrows K and H.

Unlike the second portion 1010B of the external fixator 1000, the secondportion 1010C of the external fixator 2000 holds a set of one or morefixation pins via a set of one or more pin holes 1142 provided in apin-holder 1143. The pin-holder is provided within the internal bore1111C of the second portion 1010C and is longitudinally movable withinthe internal bore 1111C. Similar to the pin-holder 143 in the firstportion 1010A, the pin-holder 1143 also comprises a set of set screws1186 for locking the fixation pins in the pin holes 1142. The set screws1186 are threaded into the pin-holder 1143 in orthogonal direction tothe pin holes 1142 and urges against the fixation pins extending throughthe pin holes 1142 to lock the fixation pins within the pin holes 1142.However, unlike the pin-holder 143, the pin-holder 1143 does not have adriving screw 155 for moving the pin-holder 1143 longitudinally withinthe internal bore 1111C. Thus, the internal bore 1111C need not bethreaded. While the longitudinal position of the pin-holder 143 in thefirst portion 1010A is controlled by the use of the driving screw 155,because the pin-holder 1143 is not threadably engaged to the internalbore 1111C of the second portion 1010C, the pin-holder 1143 freelyslides within the internal bore 1111C.

The second portion 1010C is provided with at least one longitudinallyextending slot 1126 for receiving the set screws 1186. In theillustrated example, one longitudinally extending slot 1126 is shown butanother slot 1126 may be provided diametrically opposed from the oneshown. This will allow the pin-holder 1143 to be axially rotated 180degrees to change the direction of accessing the set screws 1186. Theset screws 1186 act as guide pins as the pin-holder 1143 slideslongitudinally within the internal bore 1111C. The second portion 1010Cis also provided with a pair of diametrically opposed longitudinallyextending slots 1116 (similar to the slots 116 in the first portion1010A). The longitudinally extending slots 1116 are aligned with the pinholes 1142 and thus accommodate the fixation pins inserted into the pinholes 1142. The longitudinally extending slots 1116 also guide thefixation pins as the pin-holder 1143 moves in longitudinal direction.

In one embodiment, the pin holes 142 and 1142 may have oblongcross-section for purposes of enhancing the pin locking capability ofthe pin holes 142 and 1142. The oblong cross-section may be elongated inthe direction parallel to the axial movement of the set screws 186 and1186 threading into their respective pin-holders 143 and 1143. Becausethe pin holes 1142 have oblong cross-sectional shape, the widths of thepin holes 1142 are wider than the widths of the longitudinally extendingslots 1116. This allows the fixation pins held within the pin holes 1142to be pressed against the sides of the longitudinally extending slots1116 and thus locking the position of the fixation pins and thepin-holder 1143.

As with the external fixator 1000, the external fixator 2000 can be usedfor both compression as well as distraction procedures. However, in theembodiment where the set of fixation pins held in the second portion1010C of the external fixator 2000 are not fixed longitudinally, theexternal fixator 2000 allows greater adjustability in the positioning ofthe second portion 1010C in its longitudinal direction.

FIGS. 11A, 11B, and 11C-11F show an external fixator 3000 according toanother embodiment. The external fixator 3000 includes a first portion1010A and a second portion 1010C having the same structures as the firstportion 1010A and second portion 1010C of the external fixator 2000 ofFIG. 10A. However, in the external fixator 3000, the two portions 1010Aand 1010C are linked by a double universal joint 3010. The doubleuniversal joint 3010 comprises an H-shaped body extending longitudinallybetween the two portions 1010A and 1010C. The H-shaped body of thedouble universal joint 3010 comprises two pairs of hinge legs 3011 a,3011 b and 3013 a, 3013 b joined by a middle section 3012. Each of thetwo pairs of the hinge legs 3011 a, 3011 b and 3013 a, 3013 b form auniversal joint with the hinge legs 1502 a, 1502 b and 1506 a, 1506 b.Each of the two universal joints formed are similar to the universaljoint 1500 of the external fixator 1000 of FIG. 8A and functions insimilar way to the universal joint 1500. However, because the externalfixator 3000 comprises two universal joints the angular adjustability ofthe two portions 1010A and 1010C of the external fixator 3000 isgreater.

A first universal joint is formed between the first portion 1010A andthe double universal joint 3010 by the hinge legs 1502 a, 1502 b and the3011 a, 3011 b hingeably joined by a first double-axle 1505A. Each ofthe two axes of the first double-axle 1505A are formed by the hingelocking screws 3021 and 3022 and the structure of the two axles aresimilar in structure to those formed by the hinge locking screws 1507 aand 1507 b of the external fixator 1000. The hinge locking screw 3022extends completely through the first double-axle 1505A. The hingelocking screw 3022 also may be cannulated to provide a K-wire guidehole.

A second universal joint is formed between the second portion 1010C andthe double universal joint 3010 by the hinge legs 1506 a, 1506 b and the3013 a, 3013 b hingeably joined by a second double-axle 1505B. Each ofthe two axes of the second double-axle 1505B are formed by the hingelocking screws 3023 and 3024 and the structure of the two axles aresimilar in structure to those formed by the hinge locking screws 1507 aand 1507 b of the external fixator 1000. The hinge locking screw 3024extends completely through the second double-axle 1505B. The hingelocking screw 3024 also may be cannulated to provide a K-wire guidehole.

Shown in FIGS. 12A-12D is an example of another universally flexiblejoint system 4000 that can be incorporated into the jointed fixators 5,1000, 2000 and 3000 described herein. The joint system 4000 shown is adouble jointed example. The joint system 4000 comprises two ball joints4001 and 4002 connected by a center connecting piece 4010. Each of theball joints 4001 and 4002 have terminal ends 4042A and 4042B that areconfigured to be attached to one of the two portions of the fixators.

For example, the terminal end 4042A of the ball joint 4001 can beattached to the first portion 1010A of the fixator 3000 and the terminalend 4042B of the ball joint 4002 can be attached to the second portion1010C of the fixator 3000 by any appropriate methods. In one example,the terminal ends 4042A and 4042B and the corresponding mating portionsof the first and second portions 1010A and 1010C can be configured to bepress-fitted to one another or welded together. In another example, theterminal ends 4042A and 4042B and the corresponding mating portions ofthe first and second portions 1010A and 1010C can be configured to bethreaded into each other by screw threads. In these examples, the endsof the first and second portions 1010A and 1010C having the hinge legs1502 a, 1502 b and 1506 a, 1506 b would need to be reconfiguredaccordingly to be joined to the terminal ends 4042A or 4042B.

The two ball joints 4001 and 4002 are symmetrical in structure. Thus,the details of the ball joint 4001 will be described which is equallyapplicable to the ball joint 4002. The corresponding structures in balljoint 4002 are identified in the drawings with same numbers as in theball joint 4001 with the trailing letter “B.”

The ball joint 4001 comprises a ball joint stem 4040A with a ball 4041Aat one end and the terminal end 4042A at the other end. The ball-jointstem 4040A may be provided with a flange 4043A to act as a stop when afixator portion such as 1010A is being attached to the terminal end4042A. The ball 4041A is captured in a ball housing that comprises afirst half 4030A and a second half 4020A that are configured to bethreaded into each other while capturing the ball 4041A in between thetwo halves. The first and second halves 4030A, 4020A may be cross pinnedto prevent the two halves from coming apart after assembly.

Referring to the exploded view in FIG. 12D, the first half 4030A of theball housing has an opening 4031A at one end allowing the ball-jointstem 4040A to extend through. The first half 4030A is also provided witha female thread structure 4032A. The second half 4020A of the ballhousing comprises a make thread structure 4021A for threadably matingwith the female thread structure 4032A of the first half 4030A. Thesecond half 4020A is also provided with a space 4022A for accommodatingthe ball 4041A. The second half 4020A is also provided with a threadedbore 4023A for receiving the first threaded stem 4012A of the centerconnecting piece 4010. As shown in FIGS. 12D and 12E, the space 4022A,4022B for accommodating the ball 4041A, 4041B can have spherical curvedcontour or any other contour appropriate for holding the ball 4041A,4041B within the ball housing.

FIG. 12F illustrates another embodiment of the ball-joint stem 4040A,4040B. The ball 4041A, 4041B can be provided with a threaded hole 4060and threadably attached to the threaded ball-joint stem 4040A.

The ball 4040A captured in the ball housing formed by the ball housinghalves 4020A and 4030A is initially free spinning to allow the joint tobe freely bent. To lock the ball joint 4001, the center connecting piece4010 is then used to lock the ball joint 4001 by turning the centerconnecting piece 4010 in the locking direction which threads the firstthreaded stem 4012A further into the second half 4020A of the ballhousing and urge against the ball 4041A. As shown in FIG. 12A, thecenter connecting piece 4010 is configured to have a nut-like structure4011 to facilitate turning and locking the ball joint.

Referring to the FIG. 12B, in one embodiment, all the threadedcomponents in one ball joint are threaded in the same direction.However, the threaded components in each of the two ball joints 4001 and4002 are threaded in the opposite direction with respect to each other.For example, if the threaded components in the ball joint 4001 haveleft-handed threads the threaded components in the ball joint 4002 haveright-handed threads and vice versa. This means that the two threadedstems 4012A and 4012B of the connecting piece 4010 are oppositelythreaded. This allows the user to lock both ball joints 4001 and 4002 atthe same time by turning the center connecting piece 4010 in onedirection and unlock by turning it in the opposite direction.Alternatively, the ball joints 4001 and 4002 can be locked or unlockedindependently by turning just one of the second half 4020A or 4020B withrespect to the center connecting piece 4010.

Referring to FIGS. 13A, 14A-14D, an external fixator device 1 accordingto an embodiment is disclosed. The device 1 includes one or morefixation pins 5 a each having a threaded end suitable for engaging abone piece. The fixator device includes an elongated fixator body 10having an internally threaded bore 11 extending longitudinally throughthe length of the fixator body 10. A pair of diametrically opposedlongitudinally extending slots 16 are provided in the fixator body 10. Aslidable sleeve 20 for capturing and translating the one or more firstset of fixation pins 5 a is slidably placed over the fixator body 10.

The slidable sleeve 20 has a longitudinally extending bore 21 in whichthe fixator body is slidably received. The slidable sleeve 20 can have acylindrical shape as in the examples shown in the figures however it isnot limited to the cylindrical shape. As discussed earlier, the outershape of the fixator body 10 can be any appropriate shape and thelongitudinally extending bore 21 of the sleeve 20 needs to match thatcross-sectional shape. However, the outer shape of the sleeve 20 can beany desired shape. The slidable sleeve 20 also has a pair ofdiametrically opposed holes 22 for each of the one or more fixation pins5 a to be translated and locked by the slidable sleeve 20. Each of thefixation pin 5 a passes through one pair of diametrically opposed holes22 in the slidable sleeve 20 and the diametrically opposed slots 16 inthe fixator body in an orthogonal orientation to the longitudinal axis Cof the fixator body 10. As indicated in FIGS. 13B and 14A, driving setscrew 15 is received in one end 17 of the fixator body 10 and threadedinto the internally threaded bore 11 of the fixator body. The user canmove the set screw into or out of the internally threaded bore 11 byturning the set screw with an appropriate tool. The driving set screw 15is configured at one end to receive a tool such as an hex wrench,Robertson wrench, Torx wrench (star-shaped), screw driver, etc. Forexample, the driving set screw 15 illustrated in FIG. 14A is providedwith a receptacle 14 configured to receive a Torx wrench.

FIGS. 14C and 14D are cross-sectional views of the external fixator 1 ofFIG. 13A taken through lines A-A and B-B, respectively. FIG. 14Cillustrates the fixation pin 5 a passing through the diametricallyopposed pair of holes 22 and the pair of slots 16. FIG. 14D illustratesthe driving set screw 15 being compressed against one of the fixationpins 5 a (the one labeled as 5 a′). By threading the driving set screw15 into the threaded bore 11 of the fixator body 10 in the direction ofthe arrow D, the set screw 15 will push against the fixation pin 5 a′and cause the assembly of the pins 5 a and the slidable sleeve 20 toslide or translate with respect to the fixator body 10 in the directionof the arrow D. As the fixation pins 5 a are translated, the slidablesleeve 20 maintains the pins' orientation with respect to thelongitudinal axis C of the fixator body while the diametrically opposedlongitudinal slots 16 in the fixator body 10 maintain the pins 5 aon-axis. On-axis refers to the pins 5 a traveling in the direction Dalong the longitudinal axis C of the fixator body. In this example, thefixation pins 5 a are orthogonally oriented with respect to thelongitudinal axis C. According to another aspect of the invention,however, the orientations of the fixation pins 5 a are not limited tobeing orthogonal to the longitudinal axis C. To accommodate variousarrangements of the bones being engaged with the device, each thefixation pins 5 a can be at different orientation with respect to thelongitudinal axis C and with respect to each other. In thoseembodiments, the holes 22 on the sleeve 20 will be appropriatelypositioned to accommodate the fixation pins 5 a. Each pair of holes 22for receiving one fixation pin would not be diametrically opposed. FIG.14E shows an exemplary arrangement where one of the fixation pin 5 a″ isoriented at an angle α with respect to the adjacent fixation pin 5 a sothat the pins converge. If the fixation pins are arranged in convergingconfiguration, they do not need to be threaded.

According to an embodiment, the external fixator device 1 furtherincludes at least one pair of diametrically opposed pin holes 12provided on the fixator body 10 near the fixator body's second end 18for receiving one or more second set of fixation pins 5 b through thefixator body. The second set of fixation pins 5 b are for engaging asecond bone piece. A pair of diametrically opposed pin holes 12 isprovided for each of the fixation pins 5 b. A locking set screw 25 isreceived in and threadably engages the internally threaded bore 11 ofthe fixator body for locking the second fixation pin 5 b. Because thefixation pins 5 b pass through and traverse the internally threaded bore11 via the diametrically opposing holes 12, after the one or morefixation pins 5 b are engaged in the second bone piece, the pin 5 b canbe locked in place by tightening the locking set screw 25 against theportion of the fixation pin 5 b that is inside the threaded bore 11.Unlike the fixation pin 5 a received in the first end 17 of the fixatorbody through the slidable sleeve 20, the position of the second fixationpin 5 b along the length of the fixator body 10 is fixed and notslidable in axial direction with respect to the fixator body 10.

As illustrated in FIG. 13A, when the external fixator device 1 is usedon a patient to fixate bone parts B1 and B2 to compress the fracture oran osteotomy site F (hereinafter referred to as the “bone repair site”),the adjustable or sliding end 17 of the fixator device is affixed to thebone part B1 by way of the first set of one or more fixation pins 5 aheld by the slidable sleeve 20. The second end 18 of the fixator deviceis affixed to the bone part B2 via the second set of one or morefixation pins 5 b.

Because the fixation pins 5 b in the second end 18 of the fixator deviceis not translatable or slidable, by applying a compression force againstthe first set of fixation pins 5 a by threading the first set screw 15further into the fixator body 10, the fixation pins 5 a and 5 b can bepushed towards each other. In turn, the bone parts B1 and B2 are pushedtowards each other and apply a compression force at the bone repair siteF.

Referring to FIGS. 13B and 15A-15C, an external fixator device 2according to another embodiment is described. The fixator device 2 issubstantially the same as the fixator device 1 of FIG. 13A except thatits non-slidable second end 18 of its fixator body 10 is configured witha spring-loaded pin-locking cap 30 for locking the second fixation pins5 b in the fixator device. Like the fixator device 1, the fixator body10 has at least one pair of diametrically opposed pin holes 12 near thefixator body's second end 18 for receiving a second fixation pin 5 bthrough the fixator body.

As shown in FIGS. 15A-15D, the spring-loaded pin-locking cap 30 has abody with two open ends 38, 39. The pin locking cap 30 has a bore 31 forreceiving the second end 18 of the fixator body 10. In the example shownwhere the fixator body 10 has a cylindrical shape, the bore 31 has aninside diameter that is substantially equal to the outer diameter of thefixator body 10 enabling the second end 18 of the fixator body to bereceived into the pin locking cap's first open end 38. The second openend 39 of the pin-locking cap 30 is configured to receive a lockingscrew 35 that is used to lock the second fixation pins 5 b in thefixator device. The pin-locking cap 30 also is provided with at leastone pair of diametrically opposed pin-locking slots 32. By aligning thepin-locking slots 32 and the pin holes 12 on the fixator body 10, a bonefixation pin 5 b can be inserted through the aligned pin-locking slots32 and the pin holes 12 as shown in FIG. 15C.

The second open end 39 of the pin locking cap 30 has an inwardlyextending flange portion 139 with an opening 137 for receiving thelocking screw 35 in the center. The locking screw 35 includes a headportion 35 a and a threaded shaft portion 35 b. The threads on thethreaded shaft portion 35 b matches the female threads on the threadedbore 11 of the fixator body 10 so that the locking screw 35 threads intothe threaded bore 11. The opening 137 is sufficiently large to allow thethreaded shaft portion 35 b of the locking screw 35 to extend throughthe opening 137 and into the locking cap 30 but the head portion 35 a ofthe locking screw 35 is configured and sized not to fit through theopening 137. The head portion 35 a can be configured to receive a screwdriver or other types of tools (e.g. socket wrench, Torx wrench, etc.)for turning the screw 35.

As shown in FIG. 15B, a coil spring 37 is provided within the pinlocking cap 30 and positioned between the fixator body 10 and the flangeportion 139. In an assembled but unlocked state, the coil spring 37urges against the flange portion 139 pushing the fixator body 10 and thelocking cap 30 apart but the locking screw 35 which is threaded into theinner bore 11 of the fixator body 10 holds the locking cap 30 in place.FIG. 15C shows the position of the second fixation pins 5 b with respectto the pin locking slots 32 in the unlocked state. The pins 5 b arefreely positioned in the middle of the pin locking slots 32. To lock thefixation pins 5 b, the locking screw 35 is threaded into the fixatorbody 10, which in turn pushes the pin-locking cap 30 in the samelongitudinal direction until the pin locking slots 32 press against thefixation pins 5 b preventing the fixation pins 5 b from moving as shownin FIG. 15D.

Referring to FIGS. 20A-20C, an offset pin clamp 190 for use in securingthe second set of fixation pins 5 b at the non-adjustable end 18 of thefixator body 10 according to another embodiment is disclosed. The offsetpin clamp 190 holds the second set of fixation pins 5 b offset from thefixator body 10. The fixation pins 5 b being offset from the fixatorbody 10 refers to the fact that in this embodiment, the fixation pins 5b do not go through the fixator body as in the previously describedembodiments. The offset pin clamp 190 includes a longitudinallyextending bore 191 in which the fixator body 10 is received. One or morepin holes 192 are provided in the offset pin clamp 190 for receiving andholding one or more fixation pins 5 b. The pin holes 192 are provided inthe portion of the offset pin clamp 190 above the bore 191.

Provided in combination with the pin holes 192 is a threaded hole 194for receiving a countersink-head screw 196. The threaded hole 194 isoriented orthogonal to the bore 191 and the pin holes 192. Thecountersink-head screw 196 includes a flared head 196 h and a shaft 196s. The shaft 196 s is threaded to threadably engage the hole 194.

The threaded hole 194 of the offset pin clamp 190 extends from the topsurface of the offset pin clamp 190 to the bore 191 so that thecountersink-head screw 196 can extend into the space defined by the bore191. The hole 194 includes a countersink 194 h for accommodating theflared head 196 h of the countersink-head screw 196 and a threaded lowerportion 194 t. The countersink 194 h intersects the pin holes 192forming openings 197 connecting the hole 194 and the pin holes 192. Thediameter of the pin holes 192 is appropriately sized for the fixationpins 5 b, thus allowing the fixation pins 5 b inserted into the pinholes 192 to be exposed and slightly protrude through the openings 197.Once the fixation pins 5 b are inserted into the pin holes 192, thecountersink-head screw 196 is threaded into the hole 194. The threadedportion 196 t of the countersink-head screw 196 threadably engages thethreaded lower portion 194 t of the hole 194 and the flared head 196 hof the countersink-head screw 196 will come in contact with the portionof the fixation pins 5 b that is exposed through the opening 197 andsecures the position of the fixation pins 5 b by clamping down on them.

Referring to FIG. 20C, the offset pin clamp 190 is shown in conjunctionwith a fixator body 10 that is received within the bore 191 of the clamp190. The fixation pins 5 b are held in the pin holes 192. The offset pinclamp 190 is also provided with a locking set screw 195 for securing theoffset pin clamp 190 onto the fixator body 10. The offset pin clamp 190is configured with a second threaded hole 193 for threadably receivingthe locking set screw 195. Because the offset pin clamp 190 can beplaced anywhere along the length of the fixator body 10 and axiallyrotatable about the fixator body 10 before locking its position with thelocking set screw 195, the user can adjust the location and angularattitude of the second set of fixation pins 5 b. This adds additionalversatility to the external fixator device.

Referring to FIG. 13C, according to an embodiment, an external fixationdevice 3 includes the fixator body 10 having the slidable sleeve 20,shown in FIG. 13A, for holding the first set of one or more fixationpins 5 a at first end 17 of the fixator body 10 and provided with theoffset pin clamp 190 at the second end 18 of the fixator body 10 forholding the second set of one or more fixation pins 5 b. This embodimentof the external fixation device can be used for both compression as wellas distraction of two bone pieces, one of the two bone pieces beingaffixed to the first set of fixation pins 5 a and the second bone piecebeing affixed to the second set of fixation pins 5 b.

Referring to FIGS. 16-17E, according to another embodiment, an externalfixator device 4 for fixating bone parts includes the fixator body 10,the slidable sleeve 20 for holding the first set of one or more fixationpin 5 a as shown in FIG. 13A, and a pin-holding set screw 40. Thepin-holding set screw 40 is received in one end of the fixator body 10and threadably engages the internally threaded bore 11 of the fixatorbody. The pin-holding set screw 40 includes a cam 70 that is used tolock the position of the fixation pins 5 a.

FIGS. 17A-17E show the structural details of the pin-holding set screw40 assembly. The pin-holding set screw 40 includes a cannulated threadedhead portion 55 and an elongated pin holder 43 having at least one pinhole 42 for passing the fixation pin 5 a therethrough. The elongated pinholder 43 is rotatably attached to the cannulated threaded head portion55, the pin holder 43 being in axial alignment with the longitudinalaxes of the cannulated threaded head portion 55 and the threaded bore 11of the fixator body 10 so that the threaded head portion 55 can freelyrotate about the longitudinal axis of the pin-holding set screw 40 withrespect to the elongated pin holder 43.

The threaded head portion 55 is provided with a cannula 56 extendinglongitudinally therethrough. One end of the threaded head portion 55 isconfigured with a socket 57 (see FIG. 17B) appropriately structured forreceiving a tool, such as a screw driver or one of a variety ofwrenches, for turning the head portion 55. The elongated pin holder 43is provided with a center stem 45 that extends longitudinally from oneend and extends through the cannula 56 of the threaded head portion.During assembly of the set screw 40 assembly, after the center stem 45is inserted through the cannula 56, the tip 46 of the center stem 45 ispeened or appropriately flared as shown in the cross-sectional view inFIG. 17C to hold the pin holder 43 and the threaded head portion 55together. The attachment, however, is sufficiently loose so that thethreaded head portion 55 and the pin holder 43 axially rotate withrespect to each other. The center stem 45 effectively functions as therotational axle for the threaded head portion 55. The inner surface ofthe cannula 56 and the outer surface of the center stem 45 areappropriately finished to minimize any friction between the twocontacting surfaces.

The pin-holding set screw 40 is inserted, with the pin holder 43 first,into the threaded bore 11 near the adjustable end 17 of the fixator body10 so that the pin holes 42 provided in the pin holder 43 is accessiblethrough the longitudinal slots 16 of the fixator body 10. After theslidable sleeve 20 is slid over the fixator body 10, the pin holes 22 inthe slidable sleeve 20 and the pin holes 42 in the pin holder 43 arealigned with the longitudinal slots 16 so that fixation pins 5 a can beinserted through each pair of the diametrically opposed pin holes 22 ofthe sleeve 20 while passing through the pin holes 42 in the pin-holdingshaft 43 as shown in FIG. 16. Assembled in this manner, because thecannulated threaded head portion 55 is configured to threadably engagethe threaded bore 11, by turning the threaded head portion 55, thepin-holding set screw 40 can be translated in axial direction within thethreaded bore 11.

The pin holes 42 provided on the pin-holding shaft 43, if there are morethan one, are spaced apart appropriately and bore through thelongitudinal axis of the pin holder 43 to align with the one or morepairs of the pin holes 22 provided in the slidable sleeve 20. Thisallows the fixation pins 5 a to be inserted through the diametricallyopposed pairs of pin holes 22, the longitudinal slots 16, and the pinholes 42 when the pin-holding set screw 40 is positioned inside thefixator body 10. Because the pin holder 43 and the threaded head portion55 are rotatable with respect to each other, the threaded head portion55 can be turned within the threaded bore 11 while the first set of oneor more fixation pins 5 a are held by the slidable sleeve 20 and the pinholder 43. By turning the threaded head portion 55, the threadengagement between the head portion 55 and the threaded bore 11 allowsthe whole sliding assembly of the pin-holding set screw 40, the fixationpins 5 a and the slidable sleeve 20 to slide up and down the fixatorbody 10 along the path defined by the longitudinal slots 16.

From the assembly described above, it will be understood that theorientation of the fixation pins 5 a with respect to the fixator body 10is determined by the configuration of the pin holes 22 in the slidablesleeve 20 and the pin holes 42 in the pin-holding set screw 40. In anembodiment, that orientation is orthogonal to the longitudinal axis C ofthe fixator body 10.

The elongated pin holder 43 is also provided with a camshaft receivinghole 44 near its end opposite from the center stem 45. In the assembledstate of the external fixation device 4, a cam 70 is received into thecamshaft receiving hole 44. As shown in FIG. 17D, the cam 70 has acamshaft portion 74 which is rotatably fitted into the camshaftreceiving hole 44. The camshaft receiving hole 44 is spaced apart fromthe pin holes 42 by a desired distance so that when the fixation pins 5a are positioned through the slidable sleeve 20 and the pin holder 43,the cam 70 is located adjacent to the slidable sleeve 20 as shown inFIG. 16.

As shown in the end view of the cam in FIG. 17E, the camshaft portion 74is off-centered with respect to the cam 70 thus providing the cam actionwhen the cam is turned. Preferably, the cam 70 is in contact with theslidable sleeve 20 when the cam 70 is in an unlocked position withoutany space between the cam 70 and the slidable sleeve 20, which allowsimmediate cam action as the cam 70 is turned from the unlocked positionto the locked position. Preferably, the cam 70 is provided with a socket73 appropriately shaped for receiving a tool for turning the cam 70.

As shown in FIG. 16, the non-slidable end 18 of the external fixator 4can be configured similar to the non-slidable end 18 of the externalfixator 1 illustrated in FIG. 13A. The second set of one or morefixation pins 5 b are inserted through the at least one pair ofdiametrically opposed pin holes 12 provided in the fixator body 10 andlocked with the locking set screw 25 threadably engaged into thethreaded bore 11 from the non-slidable end 18.

In affixing the external fixator 4 to the bone pieces to be repaired,the first set of fixation pins 5 a are placed in a desired position(typically defined by their distance from the second set of fixationpins 5 b that are held at the other end of the fixator body 10) on thefixator body 10. The first set of one or more fixation pins 5 a and thesecond set of one or more fixation pins 5 b are affixed into theirrespective bone parts by threading the fixation pins into the boneparts. Once the fixation pins 5 a and 5 b are affixed into theirrespective bone parts, the second set of fixation pins 5 b are locked.The second set of fixation pins 5 b can be locked at the non-adjustableend 18 of the fixator body 10 by the same means described above inconnection with the embodiments shown in FIGS. 13A and 13B. The firstset of fixation pins 5 a are locked by the use of the cam 70 asdescribed above. Then the bone parts are compressed by threading thepin-holding set screw 40 into the fixator body 10 and urging against thefirst set of fixation pins 5 a.

According to another embodiment, the external fixator 4 includes theslidable sleeve 20 and the cam 70 as shown in FIG. 16 but thenon-slidable end 18 of the device is configured as shown in theembodiments of FIGS. 13B and 15A-15D for holding the second set of oneor more fixation pins 5 b.

According to another embodiment, the external fixator 4 includes theslidable sleeve 20 and the cam 70 as shown in FIG. 16 but thenon-slidable end 18 of the device is configured with the offset pinclamp 190 shown in FIGS. 20A-20C for holding the second set of one ormore fixation pins 5 b.

Referring to FIGS. 18A and 18B, another embodiment of a slidable sleeve60 for use in conjunction with the pin-holding set screw 40 isdisclosed. Similar to the slidable sleeve 20 of FIG. 16, the slidablesleeve 60 is provided with at least one pair of diametrically opposedpin holes 62 for receiving a fixation pin 5 a. The slidable sleeve 60 isprovided with an additional pair of diametrically opposed holes 63, 64are provided for receiving the cam 70. The camshaft 74 extends throughthe front-side hole 63 on the slidable sleeve 60, through the camshaftreceiving hole 44 of the pin-holding shaft 43, and rotatably fitted intothe back-side hole 64 so that the cam 70 can be turned between its lockand unlock positions. The holes 63, 64 and 44 are positioned withrespect to the fixation pin holes 62 and 42 such that the cam 70 issufficiently close to the adjacent fixation pin 5 a to lock the fixationpin. As with the external fixation device 4 of FIG. 16, the second setof fixation pins 5 b at the non-adjustable end 18 of the fixator body 10can be locked by the same means described above in connection with theembodiments shown in FIGS. 13A and 13B.

According to another embodiment, an external fixation device includesthe fixator body 10, the slidable sleeve 60 described above for holdingthe first set of one or more fixation pins 5 a and at least one pair ofdiametrically opposed pin holes 12 provided on the fixator body 10 nearthe fixator body's second end 18 similar to the external fixator device1 of FIG. 13A. Each pair of diametrically opposed pin holes 12 are forreceiving a second fixation pin 5 b.

According to another embodiment, an external fixation device includesthe fixator body 10, the slidable sleeve 60 described above for holdingthe first set of one or more fixation pins 5 a and the spring-loadedpin-locking cap 30 described above in reference to FIG. 13B for lockingthe second set of fixation pins 5 b at the non-adjustable end 18 of thefixator body 10.

According to another embodiment, an external fixation device includesthe fixator body 10, the slidable sleeve 60 described above for holdingthe first set of one or more fixation pins 5 a and the offset pin clamp190 described above in reference to FIGS. 20A-20C for holding the secondset of one or more fixation pins 5 b at the non-slidable end 18 of thefixator body 10.

Referring to FIGS. 19A-19D, another embodiment of a slidable sleeve 90for use in conjunction with the fixator body 10 is disclosed. Theslidable sleeve 90 includes a longitudinally extending bore 91 in whichthe fixator body 10 is slidably received. One or more pin holes 92 areprovided in the slidable sleeve 90 for receiving and holding one or morefixation pins 5 a and the slidable sleeve 90 is configured to hold thefixation pins 5 a offset from the fixator body 10. The fixation pins 5 abeing offset from the fixator body 10 refers to the fact that in thisembodiment, the fixation pins 5 a do not go through the fixator body 10as in the case of the slidable sleeves 20 and 60. This is shown in FIG.19B, which is a longitudinal cross-sectional view of the slidable sleeve90. The pin holes 92 are provided in the portion of the slidable sleeve90 above the bore 91 i.e. offset from the bore 91.

Provided in combination with the pin holes 92 is a threaded hole 94 forreceiving a countersink-head screw 96. The threaded hole 94 is orientedorthogonal to the bore 91 and the pin holes 92. FIG. 19C is anillustration of an exemplary countersink-head screw 96. The screw 96includes a flared head 96 h and a shaft 96 s. The shaft 96 s may bethreaded to threadably engage the hole 94. Preferably, the shaft 96 shas a threaded portion 96 t near the head 96 h and the remainder of theshaft is not threaded.

The threaded hole 94 of the slidable sleeve 90 extends from the topsurface of the slidable sleeve 90 to the bore 91 so that thecountersink-head screw 96 can extend into the space defined by the bore91. The hole 94 includes a countersink 94 h for accommodating the flaredhead 96 h of the countersink-head screw 96 and a threaded lower portion94 t. The countersink 94 h intersects the pin holes 92 forming openings97 connecting the hole 94 and the pin holes 92. The diameter of the pinholes 92 is appropriately sized for the fixation pins 5 a thus allowingthe fixation pins 5 a inserted into the pin holes 92 to be exposed andprotrude through the openings 97. Once the fixation pins 5 a areinserted into the pin holes 92, the countersink-head screw 96 isthreaded into the hole 94. The threaded portion 96 t of thecountersink-head screw 96 threadably engages the threaded lower portion94 t of the hole 94 and the flared head 96 h of the countersink-headscrew 96 will come in contact with the portion of the fixation pins 5 athat is exposed through the openings 97 and clamp down on the fixationpins 5 a.

Referring to FIG. 19D, the slidable sleeve 90 is shown in conjunctionwith a fixator body 10 that is received within the bore 91 of the sleeve90 and fixation pins 5 a are held in the pin holes 92. When thecountersink-head screw 96 is threaded into the hole 94 for clamping thefixation pins 5 a as shown, the unthreaded shaft portion 96 s of thecountersink-head screw extends through the longitudinal slots 16 of thefixator body and into the threaded bore 11 of the fixator body 10. Byusing the driving set screw 15 threaded into the bore 11 of the fixatorbody 10, the slidable sleeve 90 and, thus, the fixation pins 5 a, can bemoved by engaging and pushing the shaft 96 s of the countersink-headscrew 96. Preferably, the portion of the shaft 96 s that comes incontact with the driving set screw 15 is not threaded so that thecontact engagement between the set screw and the shaft 96 s is smooth.

The pin holes 92 extend through the slidable sleeve 90 at an anglegenerally orthogonal to the fixator body 10 as shown in FIG. 19A.However, the pin holes 92 can be oriented in the slidable sleeve 90 atdifferent angles with respect to the fixator body 10 as desired forparticular applications.

According to an embodiment, an external fixation device includes thefixator body 10, the slidable sleeve 90 described above for holding thefirst set of one or more fixation pins 5 a and at least one pair ofdiametrically opposed pin holes 12 provided on the fixator body 10 nearthe fixator body's second end 18 similar to the external fixation device1 of FIG. 13A. Each pair of diametrically opposed pin holes 12 are forreceiving a second fixation pin 5 b. As in the fixation device 1, afterthe fixation pin 5 b is engaged in a bone part, the second set of one ormore fixation pins 5 b can be locked in place by tightening the lockingset screw 25 against the portion of the fixation pin 5 b that istraversing through the threaded bore 11.

According to another embodiment, an external fixation device includesthe fixator body 10, the slidable sleeve 90 described above for holdingthe first set of one or more fixation pins 5 a and the spring-loadedpin-locking cap 30 described above for locking the second set of one ormore fixation pins 5 b at the non-adjustable end 18 of the fixator body10.

In another embodiment, the longitudinal slots 16 extend along asubstantial portion of the length of the fixator body 10 and two of theslidable sleeves 90 are provided on the fixator body 10 to allow thedevice to be used as a bone compression device. Each of the two slidablesleeves 90 would hold a set of one or more fixation pins 5 a. With thetwo sets of fixation pins affixed to their respective bone pieces, theslidable sleeves 90 can be urged toward each other to compress the twobone pieces together.

Referring to FIG. 22, according to another embodiment, an externalfixator device 6 may include an elongated fixator body 10, a slidablesleeve 90 of FIG. 19A at one end of the fixator body 10 holding thefirst set of fixation pins 5 a and cooperating with the longitudinalslots 16 of the fixator body 10, and an offset pin clamp 190, describedabove in reference to FIGS. 20A-20C, at the second end 18 of the fixatorbody for holding the second set of one or more fixation pins 5 b. Thesecond set of fixation pins 5 b can be affixed to a bone part B1 andlocked into position on the fixator body 10 by way of the offset pinclamp 190. The first set of one or more fixation pins 5 a can be affixedto a second bone part B2 and attached to the fixator body 10 via theslidable sleeve 90. This external fixator device 6 can be used fordistraction or compression of the two bone parts by threading a setscrew 15 into the threaded bore 11 of the fixator body 10 from theappropriate end of the fixator body 10 with respect to the slidablesleeve 90.

For example, by inserting and threading the set screw 15 at the firstend 17 of the fixator body 10, the fixator 6 can be used to put the twobone parts B1, B2 in compression by pushing the slidable sleeve 90 (andthus the first set of fixation pins 5 a) towards the offset pin clamp190. By inserting and threading the set screw 15 at the second end 18 ofthe fixator body 10, the fixator 6 can be used to distract the two boneparts B1, B2 apart by pushing the slidable sleeve 90 away from theoffset pin clamp 190. The set screw 15 can be inserted into the threadedbore 11 of the fixator body 10 from the second end 18 because the offsetpin clamp 190 does not have any components that protrude into thethreaded bore 11. The mechanism by which the slidable sleeve 90 is movedalong the fixator body 10 using the set screw 15 is described above inconnection with FIGS. 19A-19D.

Referring to FIG. 21, two or more offset pin clamps 190 can be used witha fixator body 100 to configure an external fixator device 5 where thefixation pins held by each of the offset pin clamps can be adjusted toany location along the length of the fixator body 100. Because theoffset pin clamp 190 does not require any of its components to protrudeinto its longitudinally extending bore 191, the fixator body 100 can bea hollow tube or a solid rod.

Referring to FIG. 23A, a rotatable pin clamp 290 that can be used incombination with the slidable sleeve 90 or the offset pin clamp 190 isdisclosed. FIG. 23A shows the rotatable pin clamp 290 that is assembledin combination with the slidable sleeve 90 described earlier inconnection with FIGS. 19A-19D. The rotatable pin clamp 290 is configuredto hold an additional set of one or more fixation pins 5 c in additionto the one or more fixation pins 5 a held by the slidable sleeve 90. Therotatable pin clamp 290 is configured to be rotated about thelongitudinal axis of the countersink-head screw 96 as represented by thearrow R in FIG. 23A.

As illustrated, the rotatable pin clamp 290 holds another set of one ormore fixation pins 5 c further offset (with respect to the first set ofone or more fixation pins 5 a) from the fixator body 10. This providesadditional adjustability and adaptability to the external fixationdevice by allowing the fixation pins 5 c to be affixed to bone partspositioned at different orientation with respect to the externalfixation device. FIG. 23B shows the rotatable pin clamp 290 that isassembled in combination with the offset pin clamp 190 discussed earlierin connection with FIGS. 20A-20C and holds additional set of one or morefixation pins 5 d.

FIG. 23D is a more detailed illustration of the rotatable pin clamp 290.The exemplary rotatable pin clamp 290 illustrated has a disc-shaped bodybut it can have any outline shape as appropriate. The clamp 290 includesa top side 291 and a bottom side 293 and is provided with a hole 294extending from the top side 291 to the bottom side 293 for receiving thecountersink-head screw 96. On the bottom side 293 of the clamp 290 is aprotruding flange 298 around the hole 294. The contour of the protrudingflange 298 mirrors the contour of the countersinks 94 h, 194 h of theslidable sleeve 90 and the offset pin clamp 190, respectively. The hole294 is configured with a countersink at its top side for receiving theflared head 96 h, 196 h of the countersink-head screws 96, 196.

As shown in the cross-sectional view FIG. 23C, when the rotatable pinclamp 290 is stacked on top of the offset pin clamp 190 the protrudingflange 298 mates into the countersink 194 h of the offset pin clamp 190and the hole 294 functions as an extension of the hole 194 of the offsetpin clamp 190. Preferably, the hole 294 is not threaded and when thecountersink-head screw 196 is inserted into the hole 294 thecountersink-head screw 196 threadably engages the threaded portion 194 tof the hole 194 in the offset pin clamp 190. Thus, the first fixationpins 5 a held in the pin holes 192 and the fixation pins 5 c held in thepin holes 292 of the rotatable pin clamp 290 are clamped and secured bythreading the countersink-head screw 196 into the hole 194. The flaredhead 196 h will clamp down on the fixation pins 5 c held in the pinholes 292 and in turn the protruding flange 298 will clamp down on thefixation pins 5 a held in the pin holes 192.

In the embodiment where a rotatable pin clamp 290 is assembled incombination with the slidable sleeve 90, the cross-sectional structureis similar to the one shown in FIG. 23C except that the slidable sleeve90 does not have the second threaded hole 193 for threadably receiving alocking set screw 195.

The embodiments described in the foregoing disclosure are presented asexamples. The scope of the present invention is to be limited only bythe following claims.

What is claimed is:
 1. An orthopedic device comprising: a first set ofone or more bone fixation pins suitable for engaging a bone piece; afixator body having a first part and a second part, each of the firstand second parts having an internally threaded bore extendinglongitudinally therethrough; a universal joint connecting the first partand the second part, wherein the universal joint comprising adouble-axle member providing two axes of rotation for the universaljoint; and a cannulated hinge-locking pin extending completely throughthe double-axle along one of the two axes of rotation, the cannulatedhinge-locking pin providing a cannula for receiving a K-wire; a pair ofopposed longitudinally extending slots provided in the first part of thefixator body; a pin-holder received within the first part of the fixatorbody and threadably engaging the internally threaded bore of the firstpart of the fixator body, the pin-holder configured to removably holdthe first set of one or more bone fixation pins, said fixation pinsextending through said pair of slots opposed from one another via saidpin-holder, wherein said pin-holder is longitudinally movable within thefirst part of the fixator body, whereby the position of the first set ofone or more bone fixation pins along the fixator body's longitudinalaxis is controlled; at least a pair of opposed pin holes provided in thesecond part of the fixator body for receiving a second set of one ormore bone fixation pins through the second part of the fixator body; anda set screw received in the second part of the fixator body andthreadably engaging the internally threaded bore of the second part ofthe fixator body for locking the second set of one or more bone fixationpins.
 2. The device of claim 1, wherein the pin-holder further comprisesa driving screw rotatably attached to the pin-holder and threadablyengaging the threaded bore of the fixator body for moving the pin-holderlongitudinally within the fixator body.